FINAL UPDATE: The issue was fixed yesterday at 7.30 PM PSTWe've sent 25 Epic Boss energy points to all players.Thanks again for your patience!

UPDATE: The issue should be fixed by 9pm PST.

Dear Knights,

We are aware that there's a problem when battling the Epic Boss.The devs are currently working on a fix.In the meantime, do not attempt to battle him since it will consume your energy points.Stay tuned for the latest announcements.

Ive heard of people having this problem. I myself dont have too many issues since i upgraded my phone. So it could be a problem with memory or space on your phone or just the server ability to translate to your phone. Like i said after upgrade i only have minor issues now.